Production of printing surfaces



Oct. 16, 1962 J. H. LEMCHE PRODUCTION OF PRINTING SURFACES 2 Sheets-Sheet 1 Filed Feb. 8, 1960 x 5 4 n 058 4 7 M w? o? 221 F QQ/Qo QOQO/QQQQQQFQQQQQQQ o r r .||fl. ..|0X

4 M1 )0 a 4 w a 4 4 7 I .v. P... Y 4 W0O.$JOOOOOOOQOOOOOOOOOOOJ/OO wk r d 2 Inventor Quid/w 7M M BY Maw 7%,; Attorneys Oct. 16, 1962 J. H. LEMCHE PRODUCTION OF PRINTING SURFACES 2 Sheets-Sheet 2 Filed Feb. 8. 1960 I rwenlor W M M MW; Atlorneyr United States Patent l 3,658,406 PRGDUCTION @F PRINTENG ACES Johan Henrik Lemche, Copenhagen, Denmark, assiguor to Cartoprint A/S, Copenhagen, Denmark Filed Feb. 8, 196%, Ser. No. 7,210 Claims priority, application Great Britain Feb. 9, 1959 1 Claim. (CI. 95-45) This invention relates to the production of printing surfaces which include or comprise lines of type matter. In the setting up of such lines of type matter the question of what is known in the printing art as justification arises: such justification involves letter justification by which the letters of a Word are spaced according to their form and line justification which involves the spacing of the worlds to produce a line of a predetermined length to conform to other lines.

The present invention is based on the fact that the more important justification is that of line justification, letter justification being of relatively small importance in the appearance of an assemblage of lines of type as long as line justi-fication is achieved. The present invention makes use of this fact by setting-up without length justification lines of type on a sheet or Web as by a typewriter, in optically projecting the set-up lines of type on to a photographic surface employed in the production of the printing surface and in adjusting the optical system to cause the projected image of the lines of type to conform to a prescribed length, i.e. to achieve line justification of the projected images.

It; has been found that, by this simple means, the appearance of a reproduction formed by a printing surface produced from the compensated projected image has an appearance which compares very favourably with a reproduction produced when the normal laborious letter and line justification is used.

Usually the optical apparatus would include means which makes a response to the length of the lines of type as they are about to be projected, the response being used so automatically to control the projection as to expand or to contract the projected image to effect the desired line justification.

The lines of type would usually be typed on a length of paper or some such material which is advanced stepby-step so as to bring the lines of typed matter successively into the field of an optical projection system. The projection apparatus includes means to advance a photographic material step-by-step in conformity with the step-by-step movement of the paper, the photographic material being subsequently used in the production of the printing surface by any of the known techniques.

The measurement of the length of the lines of type as they are presented in succession ready for projection by the projection system and the resulting control of the expansion or contraction of the length of the projected line of type can be achieved in different ways. In a preferred form the line of type at the position ready for projection is scanned by a spot of safe light: during this scanning, the projection lens is constantly being adjusted to vary the length of a projected image: a photo cell responsive to the safe light is trained on the paper sheet which bears special marks which when the sheet is being typed are placed on the sheet just after the last letter of a line. The position on the sheet of these marks is thus indicative of the lengths of the various lines of type. The photo-cell is arranged to control a flash lamp which emits a beam of light to. illuminate the line of type in the projection position.

Thus when the spot of safe light illuminates the special mark at the end of each line of type, the photo-cell is activated and the line of type is illuminated: during the time that the spot of light is being moved along the line 3,s5s,406 Patented Oct. 16, 1962 of type (up to the moment the flash. lamp is energised). the projection lens is being adjusted: the direction of adjustment is chosen so that at the moment the flash lamp is energised the adjustment has reached a point at which the projected image of the line of type has been expanded or contracted so as to have the required length.

It will be understood that the adjustment of the lens starts from a point of maximum expansion of an image so that, as the spot of light scans a' line which is short it will be expanded to the maximum whereas in the case of a line which is long it will be expanded to a minimum, i.e. relatively to the expansion of the short line it will be contracted: a line which is of the required length on projection will fall between the two extremes one of expansion and the other of contraction.

The ends of the lines which have been contracted or expanded to achieve line justification would, with an uncorrected optical system, be slightly staggered as compared with the ends of a line which has not been expanded or contracted. It is proposed therefore by this invention also to provide a compensating lens which will be operated to an extent dependent on the amount of justification required so as to displace the justified image as it is projected to bring one end (usually the left hand end) into vertical alignment with the ends of the other lines.

It is desirable to advance the surface (cg. the film) on to which the image is projected only after a check has been made that the line of type matter which is about to be projected has been examined and approved: it will be appreciated that in preparing a printing surface such a check is made by the typist or by a proof-reader to ensure that the contents of the line read correctly but Where many lines of typed matter are involved, it is easily possible for one or more lines to be missed.

It is proposed as a further feature of this invention to arrange that the sheet which contains the composition of lines of type to be projected shall be marked by the typist or the proof-reader as he checks each line and it i s also proposed to equip the projection apparatus with a device which is responsive to the absence of such a mark and operates to interrupt the projection of images on the film until such a mark is presented by the advance of the paper. 7

Such a response can be made by a photo-electric cell which is trained on to the edge of the strip of paper at which edge provision is made for the marking when the appropriate line of type has been examined. This photo cell operates through a control circuit to interrupt the drive to the film advancing mechanism as by the use of a magnetic clutch, the intermittent drive to the paper strip continuing. The same result can be obtained by the presence of such a mark which is applied against a line of typed matter when that line is not to be projected.

It follows that when the film has been prevented from being advanced, then as the strip having the typed lines on it is still advanced the images of at least two lines of type matter will be projected and superposed on one another on the film making it evident that this section of the film must be cut out and replaced by a strip having the image of a checked line. This arrangement would thus have an important practical advantage in not stopping the continuous advance by the paper strip for it would merely be necessary to examine the film (as would be usual practice in any case) to discover lines of type which are faulty in having superposed images on two or more lines of type.

It would however be possible to arrange that the absence of a check indication on the paper strip would operate to prevent an unchecked line of type from being projected on to the film at all.

The invention is illustrated in the accompanying drawings in which FIGURE 1 shows a part of a length of paper strip which has been prepared in a type-writing machine for the purpose of the invention and FIGURE 2 is a somewhat diagrammatic plan view of the projection apparatus Referring firstly to FIGURE 1, a strip 1 of paper having feed perforations 2 is prepared on a type-writing machine to have lines 3 of type matter: in the production of the lines 3 of type the various lines will have lengths depending on the characters used in the composition and the number of words with their space requirements: at the finish of each line the operator strikes a key on the type-writer to make a mark 4, the various marks thus indicating the lengths of the various lines.

The thus prepared strip 1 is fed step-by-step through the machine shown in FIGURE 2. This machine has an advancing sprocket 5 to engage the perforations 2, the sprocket being intermittently driven through a device indicated at 5 from a spindle 7 driven by a motor 6 and having a gear 8 transmitting drive to the device 5. The spindle 7 also drives through gearing 9 a device 10' for intermittently driving the sprocket 10 for advancing a film 11 on to which lines of typed matter are to be projected from the strip 1, the intermittent advance of the paper 1 and the film 11 occurring at the same time.

The machine shown in FIGURE 2 comprises a scanning head 12 consisting of a filament lamp 13 and a photoelectric cell 14, the head being mounted on a pivot 15 and being oscillated by a cam 16 on a spindle 17 driven through gearing 18 from the spindle 7: the lamp 113 has a light filter so that the ray of light issued by the lamp is a safe light such as infra-red having no effect on the sensitised surface of the film 11. The lamp 13 and the photo-cell 14 are focused at a point on to the transverse line of type on the strip 1 and hence on the line containing the marks 4 indicative of the length of the various lines. Thus the cam 16 causes the focused point of light issuing from the lamp 13 and its reflected ray of light received by the cell 14 to scan each line 3 of typed matter until when it passes on to the mark 4 this photo-cell will now receive an impulse: this impulse is used to determine when, in the scan, the line of typed matter will be illuminated for projection on to the film 11: this illumination is effected by a flash lamp 19 which (when the impulse is transmitted by the photo-cell) is energized through a line 20' including an amplifier 20 and a trigger device 21 of any usual form.

At the same time that the line of typed matter is being scanned by the point of light a projection lens system is being operated to control the length of the line of type matter which will be projected on the film 11 when the line is illuminated by the lamp 19. This lens system comprises lenses 22, 23, 24 and receives the image of the line of type when illuminated and projects the image forward by parallel rays to a projection lens 25 project- 5 ing the image onto the film 11. For the purpose of this invention, prisms 26, 27 are disposed between the lenses 24 and 25 and these prisms are continuously operated to expand the image which is projected to the prisms by the lens 24: the operation of the prisms is effected by earns 28, 29 on a shaft 30 driven through gearing 31 from the spindle 7, the cams operating on the prisms through arms 32, 33 to rock the prisms about pivots 34, 35 against restoring springs 34', 35'.

When the prisms are parallel no change in the length of the projected image will take place but when the prisms are pivoted one way or the other from parallelism the image will be either compressed or expanded.

Thus while a line 3 of typed matter is being scanned, the prisms 26, 27 are being continuously operated in readiness to transmit to the projecting lens 25 an image; the moment in the movement of the prisms at which the lamp 19 is energised to illuminate the line of type being scanned will depend on the position of the mark 4: hence having marks 4 the length of the image applied to the film 11 at the moment of illumination by the lamp 19 will be related to the position of the mark 4 and the setting of the parts will be such that the line of type projected on to film 11 will be contracted or expanded against the datum length represented by a projected line of type of the predetermined length. In the result therefore the prisms 26, 27 serve to compensate the various lines 3 of type for variation in their lengths above and below a predetermined length of image applied to the film 11 by the projection lens 25. Hence the various lines of type created on the film 11 when developed will have a sensibly constant predetermined length. In other words, when the mark 4 of a line 3 is closer to the edge of the sheet 1 than is the mark 4 of the required length of line, the prisms will contract the image: when the mark 4 of a line is further from the edge, the prisms will expand the image.

It will be clear that the marks 4 made at the ends of the shortest lines and of the longest lines which can be justified will define the limits of the zone of justification: the zone is indicated at X for the full nominal length of line 3 and at Y for the full nominal half-length of line 3 in both cases a line which is the actual nominal length will have a mark 4 or 4 in the centre of the zone of justification so that the lamp 13 will be energised at the precise moment that the prisms 26, 27 are parallel so that the image is projected without expansion or contraction. One such line is shown and is marked 3 with its end of the line mark indicated as 4 As the compensated image will be varied in length by the amount of expansion or contraction with respect to the datum length which will be centered on the film 11, the ends of the compensated lines would be slightly staggered or out of line with the ends of the datum line: to avoid this the len 24 is controlled by a cam 36 which is moved through gearing 37 from the spindle 7 in phase with the movement of the prisms 26, 27. This movement of this lens 24 displaces the rays transmitted by it to the prisms laterally as the prisms are being moved to expand the image: here again the lateral movement will be related to the lateral position of the predetermined image of predetermined length: thus the operation of this lens 24, at the moment the flash lamp 19 illuminates the line of typed matter will have moved the projected image laterally to a position in which the left hand end of the projected image of that line of type as projected on to the film 11 is in line with the other lines of type, i.e. the lens 24 will displace the image of the line of type to the right or to the left in reference to the position of the predetermined line.

The strip 1 can also have other control functions. It may be required that certain lines are for one reason or another to be projected without justification: in such a case a mark 4 would be made for that line on the sheet 1 in the centre of the justification zone and hence would be in line with marks 4 for the actual nominal length of lines: two such lines are shown at the top of the sheet shown in FIGURE 1. The strip can be formed with holes 38' which are formed in the strip 1 if for any reason the related line 3 of typed matter is not to be projected: this is provided for in the machine shown in FIGURE 2 by a further photo-cell arrangement for the purpose of preventing the film 11 from being advanced and at the same time preventing the flash lamp 19 from being acti vated. This photo-cell is indicated at 39, and is energised by filtered filament lamp 40' when a hole 38 moves into position. The energization of this photo-cell operates through the line 41 having an amplifier 42 to disengage a clutch 43 interrupting drive to the film advancing sprocket wheel 10: this also operates through a relay 44 to cut-0E the impulse which is necessary to strike the lamp 19.

The strip 1 can also be formed with openings 45, 46 to justify lines 3 which are nominally say only half the length of the normal lines 3 of typed matter the lines To deal with such lines 3 a second head similar to the head 12; is provided, this head being indicated at 12 and its parts corresponding to the parts of the head 12 being given similar reference numerals with the index 1. The spindle 17 of this second head is also operated through the gearing 18 from the spindle 7.

The openings 45 formed in the strip 1 when the short lines of type 3 are to be aligned with the left hand end of normal lines 3 as they are projected on to the film 11: for this purpose an infra-red lamp 47' energises a photo-cell 48 when an opening 45 is in register with them: the output of the photo-cell 48 is taken by a line 49 to an amplifier 50 which operates a selector switch 51 transferring the energising circuit of the flash lamp 19 from control by the head of 12 to control by the head 12'.

The openings 46 are formed alongside the openings 45 when the images of the short lines 3 as projected on to the film are to be aligned with the right hand ends of the normal lines 3: this of course necessitates that the images of the lines 3 have to be displaced bodily to the right and this is effected by providing a further infra-red lamp '52 and photocell 5.3 the output of which is taken via a line 54 to an amplifier 55 which energises solenoid 56. This solenoid when energised moves the lens 22 bodily against the action of a return spring 57 and so causes the image projected by this lens to be displaced from left to right as is required, the line 3 being illuminated by the flash lamp 19 under the control of the impulse transmitted via the openings 45 from the lamp 47 to the photocell 48' as has been described.

It may happen that a line 3 of type matter on the sheet 1 is either too short or too long to fall within the range of adjustment: in this case a special mark can be placed on the sheet outside the range of detection of the photocells so that the flash lamp 19 is not energized and the line in question is not projected. Provision can be made to give a warning signal that this event has occurred so that a correcting action can be taken.

The setting up of the lines of type on the sheet 1 facilitates correction for it is easy to replace a faulty line of type by a correcting line it being necessary merely to paste a strip of paper on which the corrected line of type is set out over the faulty line of type.

The intermittent feed devices 5, for the strip sheet 1 and for the film 11 can be of any convenient type such as a pawl and ratchet device the pawl being oscillated by the continuous drive through the gears 8 and 9 and advancing the sprockets 5, 10 in one direction of movement and slipping over the ratchet teeth in the other direction of movement: in the case of the drive for the sprocket 10, this can be arranged for adjustment by varying the range of the action of the pawl in the driving movement so that the amount of advance of the film can be varied to give different spacings between the justified line projected by the lens 25 onto the film. Such feed devices are well known and therefore require no further description.

I claim:

In apparatus for producing length justified lines from a copy sheet having unjustified lines of different lengths and having control marks representative of the different lengths of different lines, means having a photo-sensitive surface; normally ineffective means for illuminating a line on the copy sheet which is to be justified for reflection from said copy sheet; an optical system for receiving the light transmitted from said unjustified line and projecting an image thereof upon said photo-sensitive surface, said optical system comprising a pair of light transmitting elements in the path of the transmitted light for successively receiving and transmitting the transmitted light; means mounting said elements to move to different positions relative to one another for varying the length of the image of the line formed on said photo-sensitive surface; means for moving said elements relatively; means controlled by the control mark associated with the line to be justified for rendering said illuminating means effective when said relatively movable elements are so relatively positioned as to cause the length of the line image on said photo-sensitive surface to be the predetermined justified line length; and means including a lens in said path of transmitted light and a supplementary mark on said copy sheet for varying the range of positions of said control mark along an unjustified line within which range the control mark will be effective for rendering said illuminating means effective.

References Cited in the file of this patent UNITED STATES PATENTS 791,062 Wetmore May 30, 1905 2,160,277 Neidich May 30, 1939 2,313,119 Brand Mar. 9', 1943 2,421,656 Smith June 3, 1947 2,725,803 Tansel Dec. 6, 1955 2,939,370 Bouffilh June 7, 1960 

